Compliance and Technical Assistance Program

On December 20, 2012, the U.S. EPA finalized changes to Clean Air Act (CAA) standards for area source boilers (40 CFR 63, subpart JJJJJJ) and for major source boilers (40 CFR 63, subpart DDDDD). A major source is defined as a plant site emitting or having the potential to emit (PTE) any single hazardous air pollutant (HAP) at a rate of ten (10) tons or more per year or any combination of HAPs at a rate of 25 tons or more per year. An area source of HAP emissions is any source emitting less than the major source thresholds for HAP emissions.